From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7DF9325718 for ; Fri, 31 Oct 2025 21:29:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761946149; cv=none; b=LHUXqtntSX9Ufafj56y8tTy67UZn4649f5tF6s+Tzvv0G2ffeyi97lRGyP9mh7nO2HvIdy12tJPas5kiszlPM4zVUzFAOnuRwKx1lelY6KyEoZRxtbCPRAH37VDXnbrloEgB8FWf+uq0UDlv6wmS5xOaYDv/9Cdv2u9P0UIrhqM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761946149; c=relaxed/simple; bh=6TDUN02pliVLJKXLTAEIWvwxi4bV004VGXBfK4GQerM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ev8FB9VXAPQwI8A75pOJ0sIQzWvmQ2eqJ5zeSK902HJBE5MvVi8UOeHA9p3Uaq5PTGnUNWvCGV/4TMMQUBiSmzYxH1ceu38sG8wQCp+dg+3cG75EErR/H/WPZFrZyrxsXe4AiYfOtmhROcdkvmwT8nTsTKXlO+m8P73geojd4q8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=E8mdKJeb; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="E8mdKJeb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761946148; x=1793482148; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6TDUN02pliVLJKXLTAEIWvwxi4bV004VGXBfK4GQerM=; b=E8mdKJebBclWL6Ko29kJyEC5KLzlWqZTRQLGxSyxreqNht4WXlFQbYHg X+97+ZjLB/tU4OgKaOXtzs6uJfufvaM8BbBJy2KwO4mf+dbm5catgJTi6 +G5HvUcjm0ZuCPlR72WGwMmUgx5Zpv0bqJO0+p/fPkuWRg1Cxgh1zk+0b KgjDii2fBZn3VdqkEm3Kke0AGT4gjIw/d0FWp/hhYBBIWIKye+88mhIly 08Fh63Zlnskq+KvzY4mH70Py4eZYzkVwj4uXs0EY/gBNtC08OKjx+sbpK j7ab3CInyu9Ywn76CO58Ve3M+6fNOFoMbxXj1Bo9lW+D41Gaezoxho21R w==; X-CSE-ConnectionGUID: KXYrYDQ9TMyASkarN8x49g== X-CSE-MsgGUID: 1786+ttfThupcattBU2Rzw== X-IronPort-AV: E=McAfee;i="6800,10657,11599"; a="64002419" X-IronPort-AV: E=Sophos;i="6.19,270,1754982000"; d="scan'208";a="64002419" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Oct 2025 14:29:00 -0700 X-CSE-ConnectionGUID: GEtiZICWQKalrvqvAkQQ2g== X-CSE-MsgGUID: 6/XX/7drQ86uMcflJawhwQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,270,1754982000"; d="scan'208";a="216986677" Received: from dwillia2-desk.jf.intel.com ([10.88.27.145]) by orviesa002.jf.intel.com with ESMTP; 31 Oct 2025 14:29:00 -0700 From: Dan Williams To: linux-pci@vger.kernel.org Cc: linux-coco@lists.linux.dev, gregkh@linuxfoundation.org, aik@amd.com, aneesh.kumar@kernel.org, yilun.xu@linux.intel.com, Bjorn Helgaas , Lukas Wunner , Samuel Ortiz , Jonathan Cameron Subject: [PATCH v8 8/9] PCI/IDE: Report available IDE streams Date: Fri, 31 Oct 2025 14:29:00 -0700 Message-ID: <20251031212902.2256310-9-dan.j.williams@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251031212902.2256310-1-dan.j.williams@intel.com> References: <20251031212902.2256310-1-dan.j.williams@intel.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The limited number of link-encryption (IDE) streams that a given set of host bridges supports is a platform specific detail. Provide pci_ide_init_nr_streams() as a generic facility for either platform TSM drivers, or PCI core native IDE, to report the number available streams. After invoking pci_ide_init_nr_streams() an "available_secure_streams" attribute appears in PCI host bridge sysfs to convey that count. Introduce a device-type, @pci_host_bridge_type, now that both a release method and sysfs attribute groups are being specified for all 'struct pci_host_bridge' instances. Cc: Bjorn Helgaas Cc: Lukas Wunner Cc: Samuel Ortiz Cc: Alexey Kardashevskiy Cc: Xu Yilun Acked-by: Bjorn Helgaas Reviewed-by: Jonathan Cameron Signed-off-by: Dan Williams --- .../ABI/testing/sysfs-devices-pci-host-bridge | 12 ++++ drivers/pci/pci.h | 1 + include/linux/pci-ide.h | 1 + drivers/pci/ide.c | 67 +++++++++++++++++++ drivers/pci/probe.c | 14 +++- 5 files changed, 94 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge index 2c66e5bb2bf8..b91ec3450811 100644 --- a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge +++ b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge @@ -31,3 +31,15 @@ Description: platform specific pool of stream resources shared by the Root Ports in a host bridge. See /sys/devices/pciDDDD:BB entry for details about the DDDD:BB format. + +What: pciDDDD:BB/available_secure_streams +Contact: linux-pci@vger.kernel.org +Description: + (RO) When a host bridge has Root Ports that support PCIe IDE + (link encryption and integrity protection) there may be a + limited number of Selective IDE Streams that can be used for + establishing new end-to-end secure links. This attribute + decrements upon secure link setup, and increments upon secure + link teardown. The in-use stream count is determined by counting + stream symlinks. See /sys/devices/pciDDDD:BB entry for details + about the DDDD:BB format. diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index d3f16be40102..f6ffe5ee4717 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -616,6 +616,7 @@ static inline void pci_doe_sysfs_teardown(struct pci_dev *pdev) { } #ifdef CONFIG_PCI_IDE void pci_ide_init(struct pci_dev *dev); void pci_ide_init_host_bridge(struct pci_host_bridge *hb); +extern const struct attribute_group pci_ide_attr_group; #else static inline void pci_ide_init(struct pci_dev *dev) { } static inline void pci_ide_init_host_bridge(struct pci_host_bridge *hb) { } diff --git a/include/linux/pci-ide.h b/include/linux/pci-ide.h index e638f9429bf9..85645b0a8620 100644 --- a/include/linux/pci-ide.h +++ b/include/linux/pci-ide.h @@ -63,6 +63,7 @@ struct pci_ide { const char *name; }; +void pci_ide_set_nr_streams(struct pci_host_bridge *hb, u16 nr); struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev, struct pci_ide *ide); struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev); diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c index 7643840738fe..4ae3872589fc 100644 --- a/drivers/pci/ide.c +++ b/drivers/pci/ide.c @@ -514,3 +514,70 @@ void pci_ide_init_host_bridge(struct pci_host_bridge *hb) hb->nr_ide_streams = 256; ida_init(&hb->ide_stream_ida); } + +static ssize_t available_secure_streams_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_host_bridge *hb = to_pci_host_bridge(dev); + int nr = READ_ONCE(hb->nr_ide_streams); + int avail = nr; + + if (!nr) + return -ENXIO; + + /* + * Yes, this is inefficient and racy, but it is only for occasional + * platform resource surveys. Worst case is bounded to 256 streams. + */ + for (int i = 0; i < nr; i++) + if (ida_exists(&hb->ide_stream_ida, i)) + avail--; + return sysfs_emit(buf, "%d\n", avail); +} +static DEVICE_ATTR_RO(available_secure_streams); + +static struct attribute *pci_ide_attrs[] = { + &dev_attr_available_secure_streams.attr, + NULL +}; + +static umode_t pci_ide_attr_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct pci_host_bridge *hb = to_pci_host_bridge(dev); + + if (a == &dev_attr_available_secure_streams.attr) + if (!hb->nr_ide_streams) + return 0; + + return a->mode; +} + +const struct attribute_group pci_ide_attr_group = { + .attrs = pci_ide_attrs, + .is_visible = pci_ide_attr_visible, +}; + +/** + * pci_ide_set_nr_streams() - sets size of the pool of IDE Stream resources + * @hb: host bridge boundary for the stream pool + * @nr: number of streams + * + * Platform PCI init and/or expert test module use only. Limit IDE + * Stream establishment by setting the number of stream resources + * available at the host bridge. Platform init code must set this before + * the first pci_ide_stream_alloc() call if the platform has less than the + * default of 256 streams per host-bridge. + * + * The "PCI_IDE" symbol namespace is required because this is typically + * a detail that is settled in early PCI init. I.e. this export is not + * for endpoint drivers. + */ +void pci_ide_set_nr_streams(struct pci_host_bridge *hb, u16 nr) +{ + hb->nr_ide_streams = min(nr, 256); + WARN_ON_ONCE(!ida_is_empty(&hb->ide_stream_ida)); + sysfs_update_group(&hb->dev.kobj, &pci_ide_attr_group); +} +EXPORT_SYMBOL_NS_GPL(pci_ide_set_nr_streams, "PCI_IDE"); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 93fa7ba8dfa6..cfacf5bcd073 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -653,6 +653,18 @@ static void pci_release_host_bridge_dev(struct device *dev) kfree(bridge); } +static const struct attribute_group *pci_host_bridge_groups[] = { +#ifdef CONFIG_PCI_IDE + &pci_ide_attr_group, +#endif + NULL +}; + +static const struct device_type pci_host_bridge_type = { + .groups = pci_host_bridge_groups, + .release = pci_release_host_bridge_dev, +}; + static void pci_init_host_bridge(struct pci_host_bridge *bridge) { INIT_LIST_HEAD(&bridge->windows); @@ -672,6 +684,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) bridge->native_dpc = 1; bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; bridge->native_cxl_error = 1; + bridge->dev.type = &pci_host_bridge_type; pci_ide_init_host_bridge(bridge); device_initialize(&bridge->dev); @@ -686,7 +699,6 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) return NULL; pci_init_host_bridge(bridge); - bridge->dev.release = pci_release_host_bridge_dev; return bridge; } -- 2.51.0